Fig. 3.
Development of paracellular and transcellular resistance in cultures of RTgutF and RTgutGC alone or together on electric cell substrate for impedance sensing (ECIS). Three types of culture organizations were initiated on solid plastic supports with integrated electrodes (ECIS system) as shown in the schematics at the bottom of the figure. Paracellular resistance (a, b) was determined at a low frequency and reflects cell adhesion and formation of cell–cell contacts. Transcellular resistance (c, d) was measured at high frequency and represents cell density in this specific case. In (a, c), RTgutF and RTgutGC were seeded at a moderate density (25,000 cells/cm2; confluency 50%), to monitor resistance changes during the formation of a confluent monolayer over a time period of 6 days. In (b, d), RTgutF and RTgutGC were seeded at a high density (55,000 cells/cm2; confluency 100%) each, when cultured alone or in combination for 10 days, to compare the resistances of the individual monolayers to the co-culture. Data represent the mean ± SD; n = 4. The statistical differences are denoted: p < 0.05 by *, p < 0.01 by ** and p < 0.0001 by ****